In AC motor control applications for electric vehicle traction drive, it is desirable to maintain torque accuracy within tight tolerance band, e.g. +/−5%. However, torque is typically not a directly measured quantity. Instead, it is a predicted quantity, derived from measured phase current signals, and estimated motor parameters. Therefore, having accurate current measurement and estimated motor parameters are advantageous for maintaining tight torque requirement. It is known that economical current sensors have a DC offset bias that needs to be corrected to maintain accuracy. The correction is typically performed during an off-state when no motor-current is flowing. However, if there is a drift of the DC offset characteristic during operation, the drift will go undetected and therefore uncompensated.